It is very difficult to find accurate information about the correctness and isolation levels offered by modern distributed databases, and the operational conditions required to achieve them. Developers use different terms for the same thing, the meaning of terms varies or is ambiguous, and sometimes vendors themselves do not actually know.

At Fauna, we care a lot about accurately describing which guarantees different systems actually provide. This is our effort to centralize a description of which database does what, based on publicly available information (documentation, source code, third-party analyses, and developers' comments). For consistency’s sake, we will use the terminology from Kyle Kingsbury’s explanation on the Jepsen site. The chart is ranked by the maximum multi-partition isolation level offered.

The data is based on statements about isolation levels from vendor documentation, white papers, and developer commentary, exclusive of aspirational marketing statements. We have tried to be neutral in the characterization of the various systems' architectural properties. Whether the system implementations uphold these guarantees is addressed elsewhere. If you haven't already, please see FaunaDB's own Jepsen results for confirmation that FaunaDB upholds its guarantees.